The Clbuttic Mistake: When obscenity filters go wrong

President Abraham Lincoln was buttbuttinated by an armed buttailant after a
life devoted to the reform of the US consbreastution.

By Matthew Moore

12:20PM BST 02 Sep 2008

Not an extract from an essay by a particularly poor history student, but a selection of the nonsense phrases created by automatic software designed to remove offensive words from articles posted on the internet.

Abraham Lincoln: A victim of buttbuttination?

The phenomena, known as “The Clbuttic Mistake” after a mangling of the word “classic” that is believed to be the first identified instance of the problem, can be found on tens of thousands of websites.

The error is caused by poorly programmed anti-obscenity filters – similar to spell checkers – that automatically replace words considered rude or offensive with more acceptable variants. “Butt” replaces “ass”, “breast” is substituted for “tit”, and so on.

Rudimentary versions of this software do not just replace obscene words, but also alter longer words which contain banned letter combinations, so "assassination" becomes "buttbuttination", "passenger" becomes "pbuttenger", and "passerby" becomes "pbutterby".

The problem is fairly widespread; Google searches turn up 3,810 results for “clbuttic”, 5,120 for “consbreastution”, and 1,450 for “Buttociated Press”, a corruption of the US news agency the Associated Press.

It contains mentions of a “series of previously secret Central Intelligence Agency (CIA) plots to buttbuttinate foreign leaders”, a law “pbutted by Congress”, and new powers "butterted" by the US administration.

Another article on the site is titled “What did the British Embbutty do for this British National Overseas pbuttport holder.”

The error appears particularly common on foreign sites hosting English-language articles, but a similar mistake on an American Christian news website caused international amusement earlier this year.

The American Family Association had programmed its filter to replace the word “gay” with “homosexual”, causing an article about sprinter Tyson Gay’s triumph at the US Olympic trials to begin: “Tyson Homosexual was a blur in blue, sprinting 100 meters faster than anyone ever has."

Further on in the piece the runner was referred to as “the 25-year-old Homosexual”

On the many websites and message boards devoted to identifying new instances of the Clbuttic Mistake, the greatest source of confusion appears to be the choice of banned words, and particularly whether “ass” is really more offensive than “butt”.